Monday, September 26, 2011

No NO-XPLODE- No Problem

Statistically speaking, a meta-analysis combines the results of several studies that address a set of related research hypotheses. Meta-analyses are so cool because in the process of compiling similar research studies you end up with an extremely large test pool. Having a large test pool lends legitimacy to any research study. The following meta-analysis (Doherty & Smith, 2005) combined 21 studies to explore the relationship between caffeine consumption and Rate of Perceived Exertion (RPE) during exercise.

As one would expect this meta-analysis found that caffeine does lower RPE during exercise. In comparison to placebo, caffeine reduced RPE during exercise by 5.6% (95% CI (confidence interval). The reason for the decreased RPE with exercise is pretty complex. Previous research studies indicate that caffeine’s ability to increase the central nervous systems sympathetic tone is the largest underlying reason for the observed phenomena. Manifestations of this effect include, increased respiration rate, increased heart rate, increased blood pressure and increased maximal motor unit recruitment. These factors combine to account for the decreased rate of perceived exertion at a given work rate. 


This research goes a long way in the validation of caffeine supplement claims. The interesting thing is that most caffeine products are labeled as Nitrous Oxide (NO) products but the effect of NO on human performance is negligible at best. Essentially, caffeine provides the benefit while NO serves as the cool marketing tool to suck in the consumers dollar.


  1. So you're telling me I should mix my NO-XPLODE with 12 oz of Starbucks?

  2. Precisely... If your end goal is a resting heart rate of 170, atrial fibrillation and irritable bowel syndrome. Haha, thanks for the comment.